Demonstrates failed attempt to retrieve system interfaces

results.txt

Resolving Windows.Media.Playback.IMediaPlaybackItem:
This type implements 1 interface(s).
rImpl token: 0x090002ba.
iface token: 0x010004f6. typeRef: true
iface represents: Windows.Media.Playback.IMediaPlaybackSource
ptkResolutionScope is: 0x00000001

Resolving Windows.Foundation.Collections.IPropertySet:
This type implements 3 interface(s).
rImpl token: 0x09000005.
iface token: 0x1b000006. typeRef: true
iface represents: 
ptkResolutionScope is: 0x00000000
rImpl token: 0x09000006.
iface token: 0x1b000007. typeRef: true
iface represents: 
ptkResolutionScope is: 0x00000000
rImpl token: 0x09000007.
iface token: 0x1b000008. typeRef: true
iface represents: 
ptkResolutionScope is: 0x00000000

Resolving Windows.Foundation.Collections.IObservableMap`2:
This type implements 1 interface(s).
rImpl token: 0x09000003.
iface token: 0x1b000002. typeRef: true
iface represents: 
ptkResolutionScope is: 0x00000000

winmd.dart

import 'dart:ffi';
import 'package:ffi/ffi.dart';
import 'package:win32/win32.dart';

import 'package:winmd/winmd.dart';

void main() {
  const types = <String>[
    // This works; it implements IMediaPlaybackSource
    'Windows.Media.Playback.IMediaPlaybackItem',

    // Gives interfaces but can't resolve them
    'Windows.Foundation.Collections.IPropertySet',

    // This does not work; it implements IDictionary`2, which is in mscorlib
    'Windows.Foundation.Collections.IObservableMap`2',
  ];

  for (final type in types) {
    final typeDef = MetadataStore.getMetadataForType(type)!;
    print('Resolving ${typeDef.typeName}:');

    final reader = typeDef.reader;

    // Get first implemented interface
    final phEnum = calloc<IntPtr>();
    final rImpls = calloc<Uint32>(256);
    final pcImpls = calloc<Uint32>();
    var hr =
        reader.EnumInterfaceImpls(phEnum, typeDef.token, rImpls, 256, pcImpls);
    print('This type implements ${pcImpls.value} interface(s).');
    if (FAILED(hr)) {
      throw WindowsException(hr);
    }

    for (var i = 0; i < pcImpls.value; i++) {
      final rImpl = rImpls.elementAt(i).value;
      print('rImpl token: ${rImpl.toHexString(32)}.');

      // Process interface token
      final pClass = calloc<Uint32>();
      final ptkIface = calloc<Uint32>();
      hr = reader.GetInterfaceImplProps(rImpl, pClass, ptkIface);
      if (FAILED(hr)) {
        throw WindowsException(hr);
      }

      final iface = ptkIface.value;
      print('iface token: ${iface.toHexString(32)}. '
          'typeRef: ${tokenIsTypeRef(iface)}');

      // Resolve interface token
      final ptkResolutionScope = calloc<Uint32>();
      final szName = calloc<Uint16>(256).cast<Utf16>();
      final pchName = calloc<Uint32>();
      hr = reader.GetTypeRefProps(
          iface, ptkResolutionScope, szName, 256, pchName);
      if (FAILED(hr)) {
        throw WindowsException(hr);
      }
      print('iface represents: ${szName.toDartString()}');
      print(
          'ptkResolutionScope is: ${ptkResolutionScope.value.toHexString(32)}');
    }
    print('');
  }
}